Thalidomide attenuates nitric oxide‐driven angiogenesis by interacting with soluble guanylyl cyclase

Abstract

Background and purpose: Nitric oxide (NO) promotes angiogenesis by activating endothelial cells. Thalidomide arrests angiogenesis by interacting with the NO pathway, but its putative targets are not known. Here, we have attempted to identify these targets. Experimental approach: Cell-based angiogenesis assays (wound healing of monolayers and tube formation in ECV304, EAhy926 and bovine arterial endothelial cells), along with ex vivo and in vivo angiogenesis assays, were used to explore interactions between thalidomide and NO. We also carried out in silico homology modelling and docking studies to elucidate possible molecular interactions of thalidomide and soluble guanylyl cyclase (sGC). Key results: Thalidomide inhibited pro-angiogenic functions in endothelial cell cultures, whereas 8-bromo-cGMP, sildenafil (a phosphodiesterase inhibitor) or a NO donor [sodium nitroprusside (SNP)] increased these functions. The inhibitory effects of thalidomide were reversed by adding 8-bromo-cGMP or sildenafil, but not by SNP. Immunoassays showed a concentrationdependent decrease of cGMP in endothelial cells with thalidomide, without affecting the expression level of sGC protein. These results suggested that thalidomide inhibited the activity of sGC. Molecular modelling and docking experiments revealed that thalidomide could interact with the catalytic domain of sGC, which would explain the inhibitory effects of thalidomide on NO-dependent angiogenesis. Conclusion and implications:Our results showed that thalidomide interacted with sGC, suppressing cGMP levels in endothelial cells, thus exerting its anti-angiogenic effects. These results could lead to the formulation of thalidomide-based drugs to curb angiogenesis by targeting sGC.

Investigation of molecular mechanisms and regulatory pathways of pro-angiogenic nanorods

“…Finally, the fluorescence images of the stained cells were captured by using an Olympus fluorescence microscope. 25,26 …”

Crystal Structures of the Catalytic Domain of Human Soluble Guanylate Cyclase

“…These molecules are also thought to act by oxidation and desensitisation of the heam group to NO. A growing body of evidence has implicated sGC as a player in the angiogenesis pathway [7], [25], [27], [28], [29], [30], a popular pathway to drug in the inhibition of tumor vascularisation [31], [32] and to combat diabetic retinopathy [33], [34]. An as-yet unexploited avenue for pharmaceutical development would be targeting the catalytic domain for activation or inhibition.…”

Thalidomide in Combination with Chemotherapy in Treating Elderly Patients with Acute Myeloid Leukemia

“…It owes this potent anti-angiogenic activity to direct inhibition of endothelial cell proliferation, decreasing the plasma levels of basic fibroblast growth factor and downregulating the expression of neuropilin-1, a vascular endothelial growth factor receptor that is overexpressed in AML and shows a significant correlation with lower survival [7,8]. Majumder et al [9] showed that thalidomide attenuated nitric oxide-driven angiogenesis by interacting with soluble guanylyl cyclase. In addition to anti-angiogenic activity, thalidomide probably also has anti-leukemic effects through other mechanisms, such…”